NRG4 and metabolic dysfunction-associated steatohepatitis: In Nrg4-deficient mice with nonalcoholic steatohepatitis, cell death, inflammation, fibrosis, and liver injury are more serious because Nrg4 can positively regulate ErbB3 and ErbB4 to repress the ubiquitination and proteasomal degradation of c-FLIPL to reduce cell death (131).